2821563720 has 80 divisors (see below), whose sum is σ = 9483600060. Its totient is φ = 752416128.

The previous prime is 2821563659. The next prime is 2821563727. The reversal of 2821563720 is 273651282.

2821563720 is a `hidden beast` number, since 2 + 8 + 2 + 15 + 637 + 2 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 2802431844 + 19131876 = 52938^2 + 4374^2 .

It is a super-2 number, since 2×2821563720² = 15922443652040476800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (2821563727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 432187 + ... + 438666.

Almost surely, 2^2821563720 is an apocalyptic number.

2821563720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2821563720 is an abundant number, since it is smaller than the sum of its proper divisors (6662036340).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2821563720 is a wasteful number, since it uses less digits than its factorization.

2821563720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 870876 (or 870863 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 2821563720 is about 53118.3934245003. The cubic root of 2821563720 is about 1413.0687350771.

The spelling of 2821563720 in words is "two billion, eight hundred twenty-one million, five hundred sixty-three thousand, seven hundred twenty".